The human body is an incredibly complex and intricate system, one that still baffles doctors and researchers on a regular basis despite thousands of years of medical knowledge. As a result, it shouldn’t be any surprise that even body parts and functions we deal with every day have bizarre or unexpected facts and explanations behind them. From sneezes to fingernail growth, here are 100 weird, wacky, and interesting facts about the human body.

The Brain

The human brain is the most complex and least understood part of the human anatomy. There may be a lot we don’t know, but here are a few interesting facts that we’ve got covered.

Nerve impulses to and from the brain travel as fast as 170 miles per hour. Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.

The brain operates on the same amount of power as 10-watt light bulb. The cartoon image of a light bulb over your head when a great thought occurs isn’t too far off the mark. Your brain generates as much energy as a small light bulb even when you’re sleeping.

The human brain cell can hold 5 times as much information as the Encyclopedia Britannica. Or any other encyclopedia for that matter. Scientists have yet to settle on a definitive amount, but the storage capacity of the brain in electronic terms is thought to be between 3 or even 1,000 terabytes. The National Archives of Britain, containing over 900 years of history, only takes up 70 terabytes, making your brain’s memory power pretty darn impressive.

Your brain uses 20% of the oxygen that enters your bloodstream. The brain only makes up about 2% of our body mass, yet consumes more oxygen than any other organ in the body, making it extremely susceptible to damage related to oxygen deprivation. So breathe deep to keep your brain happy and swimming in oxygenated cells.

The brain is much more active at night than during the day. Logically, you would think that all the moving around, complicated calculations and tasks and general interaction we do on a daily basis during our working hours would take a lot more brain power than, say, lying in bed. Turns out, the opposite is true. When you turn off your brain turns on. Scientists don’t yet know why this is but you can thank the hard work of your brain while you sleep for all those pleasant dreams.

Scientists say the higher your I.Q. the more you dream. While this may be true, don’t take it as a sign you’re mentally lacking if you can’t recall your dreams. Most of us don’t remember many of our dreams and the average length of most dreams is only 2-3 seconds–barely long enough to register.

Neurons continue to grow throughout human life. For years scientists and doctors thought that brain and neural tissue couldn’t grow or regenerate. While it doesn’t act in the same manner as tissues in many other parts of the body, neurons can and do grow throughout your life, adding a whole new dimension to the study of the brain and the illnesses that affect it.

Information travels at different speeds within different types of neurons. Not all neurons are the same. There are a few different types within the body and transmission along these different kinds can be as slow as 0.5 meters/sec or as fast as 120 meters/sec.

The brain itself cannot feel pain. While the brain might be the pain center when you cut your finger or burn yourself, the brain itself does not have pain receptors and cannot feel pain. That doesn’t mean your head can’t hurt. The brain is surrounded by loads of tissues, nerves and blood vessels that are plenty receptive to pain and can give you a pounding headache.

80% of the brain is water. Your brain isn’t the firm, gray mass you’ve seen on TV. Living brain tissue is a squishy, pink and jelly-like organ thanks to the loads of blood and high water content of the tissue. So the next time you’re feeling dehydrated get a drink to keep your brain hydrated.

Hair and Nails

While they’re not a living part of your body, most people spend a good amount of time caring for their hair and nails. The next time you’re heading in for a haircut or manicure, think of these facts.

If we can all be creative, why is it so hard to come up with truly original ideas?

It's because creativity is mysterious. Just ask any scientist, artist, writer or other highly creative person to explain how they come up with brilliant ideas and, if they're honest, they don't really know.

But over the decades psychologists have given ordinary participants countless tests, forms and tasks and conducted hundreds of hours of interviews. From these emerge the psychological conditions of creativity.

These Hollywood good girls may not be as sweet as you think. While these actresses are generally known for their squeaky clean images, even they aren't immune to a scandal or two.

From drunken arrests to shocking affairs, these leading ladies all have a bad streak.

With fame and success comes temptations, and we've seen too many formerly sweet stars turn sour.
But unlike the scandal-seeking Miley Cyrus and the infamous Lindsay Lohan, these stars bounced back.

1 Reese Witherspoon

The southern actress lost all her charm when a video of her and husband Jim Toth auguring with an officer hit the Internet. Witherspoon and Toth were pulled over for drunk driving and when the cop didn't give her special treatment for being a celebrity, the actress flipped out.

She yelled, "Do you know my name sir?" He definitely found out when he wrote up the arrest report.